Machine-tool.



Patented May 29, 191?.

2 SHEETSSHEET 1.

i E EHHEEIEE IEEE 1. G. OLIVER.

MACHINE TOOL.

APPLICATION FILED FEB. 19,1916.

Patented May 29, 1917.

2 SHEETS-SHEET 2.

l. G. OLlVER.

MACHINE TOOL.

APPLICATION man FEB. 19. I9l6.

TATES PATENT @FFTQE.

JOHN G. OLIVER, OF CLEVELAND, OHIO, ASSIGNOR T0 BARDONS AND OLIVER, APART- NERSHIP COMPRISING GEORGE C. BARIDONS AND JOHN G. OLIVER, OFCLEVELAND,

OHIO.

MACHINE-TOOL.

Specification ofLetters Patent.

Patented May 29, 1.91%.

Application filed February 19, 1916. Serial No. 79,231.

To all whom it may concern:

Be it known that 1, JOHN G. OLIVER, a citizen of the United States,residing at Cleveland, in the county of Cuyahoga and State of Ohio, haveinvented a certain new and useful Improvement in Machine-Tools, of whichthe following is a full, clear, and exact description.

This is an improvement in machine tools, such as lathes, which areprovided with a live spindle to which the work may be fixed, and with atool holding slide movable transversely with respect to said livespindle for the purpose of carrying the tool toward or from the axis ofthe rotating spindle.

The invention is of particular practical value when the machine tool isused for cutting of]? pieces from a stock rod fixed to the live spindle.

The efficiency of a machine of this sort is measured by the speed atwhich it does its work. If, when the tool begins to cut off a piece froma stock rod fixed to the live spindle, said rod is rotating at a ratesuch that the surface speed of the work against the tool is as fast asdesired,which, generally speaking, is as fast as the tool will stand, itis evident that the surface speed of the work against the tool will bereduced as the tool cuts its way toward the center of the stock rod,provided the rate of rotation of the stock rod remains the same. Theresult of this reduction of the speed of surface contact of the workagainst the tool is that the tool will not cut as fast as it is capableof cutting. The object of this invention is to prevent, in aconsiderable degree, this diminution in the efiiciency of the machineand its tool; and this result is accomplished by providing the machinewith means which act automatically to increase the rate at which thework will be turned as the tool cuts its way toward the axis of thestock rod.

In the drawing Figure 1 is an end view of a lathe equipped with theinvention, and Fig. 2 is a side view of so much of said lathe as isnecessary to disclose the invention.

The drawing shows, with as much detail as is necessary, an ordinarylathe, and an ordinarv variable speed electric motor which is connectedwith the lathe in any suitable .way, as through the gears 81, 32, 33,for the purpose of driving said lathe.

Referring particularly to the lathe l0 represents the rotatable livespindle; 12 a transversely movable tool slide adapted to have cuttingofl? tool 13 secured to it; 14 represents the main carriage which isslidably mounted upon the frame work of the machine, and is movable in apath parallel with the axis of the live spindle; and it is upon thiscarriage that the tool slide is mounted. 15 represents the feed screw ofthe tool slide. This is supported upon the tool slide in. such wise thatit may be rotated, but it moves endwise with the tool slide; and it goesthrough a nut 17 which is fixed to the carriage. All of the above namedparts are well understood parts of a lathe; as is also the mechanismthrough which this tool slide feed screw may be rotated as desired, andwith the result of moving the slide toward or away from the axis of thespindle 10.

In a box 20 fixed to the main carriage is a gear train of which thereceiving terminal member is a spur gear 21 which is mounted upon andhas a tongue and groove connection with the feed screw 15. The otherterminal member of this gear train is a bevel gear 22 which is formed asa part of a sleeve 24, which sleeve is rotatably mounted in but isprevented from moving endwise with respect to the box 20.

Referring now to the motor, it is per 86 of usual construction. Itsarmature 40 is so connected with the armature shaft 30 that it may moveendwise thereon, but must rotate in unison with said shaft. A feed screw41 is mounted in the motor casing; and on it is a non-rotatable nut 42which is connected by a link 4L3 with a lever 4A that is so connectedwith the armature, that, as the lever rocks, the armature will be movedinto or out of the field of the motor, with the result of varying thespeed at which the armature and its shaft 30 will turn. These are wellunderstood parts of a certain type of variable speed motor.

We come now to the added parts which cause the automatic variation inthe speed of the motor, and consequently the speed of the lathe. A shaft50 is rotatably mounted in such wise that it can have no endwisemovement. Near one end it is mounted in a fixed bracket 51; while itsother end is sup ported by and goes through the sleeve 24 and has atongue and groove connection therewith. On one end of this shaft is asprocket wheel 53 which is connected by means of a sprocket chain Setwith a sprocket wheel 55 fixed to the outwardly jfiOjGCt lng end of thefeed screw i1,

From the foregoing it is evident that, regardless of the position of themain carriage of the lathe, motion will be transmitted from the feedscrew of the tool slide through the described train of mechanism to thearmature positioning screw 41 of the motor. The position of the armatureot' the motor with espect to its field is determined therefore, by theposition of the tool slide with respect to the axis of the live spindle.As the feed screw tor the tool slide turns to move said slide toward theplane which contains the axis of the live spindle, the armaturecontrolling screw 01 the motor will be turned in the direction such aswill cause the armature to move into the field of the motor, and therebyincrease the speed of the motor. This obviously will correspondinglyincrease the speed at which the live spindle is turned, and also thespeed at which the tool slide is moved toward the axis oi the livespindle. lherefore, it, when the cutting of? operation begins the livespindle is being turned through the lathe mechanism and by the motor ata suliiciently high rate of speed to cause the tool to cut about as fastand as deep as it can, then the tool slide is moved toward the verticalplane in which the axis of the live spindle lies, such movement beinginduced by the turning of the feed screw, the rate at which the spindleis rotated will be gradually increased; with the result that the toolwill continue to do its worir eliiciently, will do substantially all thework it can do as it works its way toward the axis of the rod which isbeing cut off, and with the result that the cutting speed of the tool iskept approximately uniform.

Having described my invention, 1 claim:

1. The combination of a lathe having a ro- Copies of this patent may beobtained for five cents each, by addressing the Commissioner of Patents,

tatablc spindle and a transversely movable tool slide, mechanism bywhlch the'tool sllde may be moved, a variable speed electric motorhaving a longitudinally movable arma ture mechanism by which the saidarmature may be moved longitudinally, and means connecting the mechanismfor moving the slide with the mechanism for moving the said armature ofthe motor, the said means including a sliding connection with themechanism which operates the slide.

2. The combination of a lathe having a rotatable spindle and atransversely movable tool slide, a variable speed electric motor havinga longitudinally movable armature and mechanism which includes arotatable member for moving said armature, a shaft operatively connectedwith said rotatable armature controlling member, and means intermediateof the feed screw of the tool slide and said shaft for turning thelatter.

3. The combination of a lathe having a rotatable live spindle, acarriage movable in a path parallel with the axis of the live spindle, atransversely movable tool slide mounted on said carriage, a feed screwon the tool slide for moving it, a gear train mounted on the carriage,one terminal member of which gear train embraces and has a tongue andgroove connection with said tool slide teed screw, a rotatable shaftwhich goes through the other terminal member of said gear train and hasa sliding tongue and groove connection therewith, a variable speedelectric mo- I tor, armature positioning mechanism. for 0 said motor,and mechanism intermediate of the last mentioned shaft and said armaturepositioning mechanism by which the latter is operated.

In testimony whereof, I hereunto afiix my signature in the presence oftwo witnesses.

JOHN G. OLIVER. Witnesses:

M. J. LLOYD, H. W. GEORGE.

Washington, D. C.

